When parking a motor vehicle which has been operated with the headlights on, the operator may unintentionally leave without realizing that the lights remain lit, especially during conditions of fog or rain. If the auto continues to stand thus for an extended period of time, drain on the battery may make the motor subsequently difficult or impossible to start. Various devices have been suggested to deal with this problem by incorporating into the wiring system a cut-off switch which is triggered by some other operation, such as ignition turn-off, door closure, release of weight from driver's seat, etc. either with or without a time-delay element. However any installation into the vehicle electric system (after it leaves the manufacturer) is both expensive and usually requires expert knowledge; even so, the result at best is a more complicated wiring system which now includes another component which may fail unexpectedly.
Accordingly it is an object of the present invention to provide such a simple and entirely mechanical switch mechanism or assembly which is readily installed on any highway vehicle with use of a simple tool such as a screwdriver and without in any way connecting with or interfering with the electric circuitry or with the existing system of turning on and off the vehicle lights, such switch being mechanically operable merely by closing the driver's door and without requiring any conscious presetting of the switch mechanism.